437 research outputs found

    Experimental L-band SST satellite communications/surveillance terminal study. Volume 1 - Study summary

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    Study of design for experimental L band supersonic transport communications/surveillance termina

    Test plan for NAVSTAR navigation system. Volume 1 - Test plan description

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    Performance test plan of radio navigation system employing satellit

    Continued study of NAVSTAR/GPS for general aviation

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    A conceptual approach for examining the full potential of Global Positioning Systems (GPS) for the general aviation community is presented. Aspects of an experimental program to demonstrate these concepts are discussed. The report concludes with the observation that the true potential of GPS can only be exploited by utilization in concert with a data link. The capability afforded by the combination of position location and reporting stimulates the concept of GPS providing the auxiliary functions of collision avoidance, and approach and landing guidance. A series of general recommendations for future NASA and civil community efforts in order to continue to support GPS for general aviation are included

    Experimental L-band SST satellite communications/surveillance terminal study. Volume 3 - Communications/surveillance analysis

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    Analysis of surveillance and communications functions of L band air traffic control satellite syste

    FMCW Signals for Radar Imaging and Channel Sounding

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    A linear / stepped frequency modulated continuous wave (FMCW) signal has for a long time been used in radar and channel sounding. A novel FMCW waveform known as “Gated FMCW” signal is proposed in this thesis for the suppression of strong undesired signals in microwave radar applications, such as: through-the-wall, ground penetrating, and medical imaging radar. In these applications the crosstalk signal between antennas and the reflections form the early interface (wall, ground surface, or skin respectively) are much stronger in magnitude compared to the backscattered signal from the target. Consequently, if not suppressed they overshadow the target’s return making detection a difficult task. Moreover, these strong unwanted reflections limit the radar’s dynamic range and might saturate or block the receiver causing the reflection from actual targets (especially targets with low radar cross section) to appear as noise. The effectiveness of the proposed waveform as a suppression technique was investigated in various radar scenarios, through numerical simulations and experiments. Comparisons of the radar images obtained for the radar system operating with the standard linear FMCW signal and with the proposed Gated FMCW waveform are also made. In addition to the radar work the application of FMCW signals to radio propagation measurements and channel characterisation in the 60 GHz and 2-6 GHz frequency bands in indoor and outdoor environments is described. The data are used to predict the bit error rate performance of the in-house built measurement based channel simulator and the results are compared with the theoretical multipath channel simulator available in Matlab

    The applications of satellites to communications, navigation and surveillance for aircraft operating over the contiguous United States. Volume 1 - Technical report

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    Satellite applications to aircraft communications, navigation, and surveillance over US including synthesized satellite network and aircraft equipment for air traffic contro

    CR-100 implementation study for space shuttle

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    Examining performance of CR-100 CRIS equipment for space shuttle us

    Experimental L-band SST satellite communications/surveillance terminal study. Volume 5 - Aircraft terminal definition

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    Aircraft terminal designs for experimental and operational supersonic transport for L band satellite air traffic contro

    Multi-Sensor Methods for Mobile Radar Motion Capture and Compensation.

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    Ph.D. Thesis. University of Hawaiʻi at Mānoa 2017

    Avionics-based GNSS integrity augmentation performance in a jamming environment

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    Intentional and unintentional radiofrequency interference (i.e., jamming) can result in degraded navigation accuracy or complete loss of the GNSS signal tracking. Jammers can be classified into three broad categories: Narrowband Jammers (NBJ), Spread Spectrum Jammers(SSJ) and Wideband Gaussian Jammers (WGJ). In recent years, a number of effective jamming detection and anti-jamming (filtering and suppression) techniques have been developed for military GNSS applications and some of them are envisaged to be used for civil purposes (e.g., terrorist attacks). The synergies between these jamming detection techniques and our newly developed Avionics-Based Integrity Augmentation (ABIA) system are investigated in this paper. In particular, GNSS vulnerability to NBJ, SSJ and WGJ types of jamming is analytically described in terms of Jamming to Signal (J/S) tracking thresholds and the models for calculating the minimum acceptable aircraft-to-jammer ranges are presented. Simulation results demonstrate that the proposed ABIA architecture is capable of performing jamming detection and avoidance when GNSS is considered as the primary source of navigation data
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